For most field service business owners, year end accounting means handing a shoebox of receipts to an accountant and hoping for the best. It works, up to a point. But the businesses that find year end painful are almost always the ones that left the record-keeping until it became urgent.
This isn’t a comprehensive accounting guide; your accountant handles the technical side. What it covers is the practical side: the deadlines, the records you need to have ready, the areas specific to field service that often catch people out, and the mistakes that tend to cost the most.
Jump to a section:
- The deadlines that matter
- Get your records straight
- Payroll year end
- CIS: what field service businesses need to know
- What you can claim
- Common mistakes
The deadlines that matter
A limited company doesn’t follow the 5 April personal tax year. Your deadlines are set by your company’s accounting year end, which you can find on Companies House.
Here’s what you’re working towards:
- Annual accounts to Companies House: due within 9 months of your year end date. These are the statutory accounts your accountant prepares: balance sheet, income statement, directors’ report.
- Corporation tax payment: due 9 months and 1 day after your year end. Most businesses aim to have their accounts finalised well before this so they know what they owe.
- Corporation tax return (CT600) to HMRC: due within 12 months of your year end. The payment date comes first, so don’t wait until the filing deadline to work out your bill.
- Confirmation statement to Companies House: due within 14 days of your confirmation statement anniversary. This confirms your company’s directors, shareholders, and registered address are up to date.
One important update: from April 2026, HMRC’s old online filing service for company tax returns closes. All CT600 submissions will need to go through commercial software. If you’re not already using an accountant or software to file, this needs sorting before then. HMRC has guidance on the transition here.
Get your records straight
Before anything else, your bookkeeping needs to be complete for the year. An accountant can only work with what you give them. Gaps or errors in your records mean extra time, extra questions, and usually a bigger bill.
Work through this before you hand anything over:
- Bank reconciliation: every transaction in your accounting software should match your bank statements. Don’t leave this until the last minute. Reconciling monthly throughout the year makes year end quick; leaving it all until March makes it painful.
- Outstanding invoices: check that every job you completed has been invoiced and recorded, and that payments received have been matched to the right invoice.
- Supplier bills: confirm that all purchase invoices are recorded, including any that arrived in the final weeks of the year. An expense that happened before your year end needs to be in the accounts for that year, even if you pay it later.
- Expenses: pull together all business costs for the year: fuel, tools, materials, insurance, software, training. If you’ve been keeping receipts and logging expenses as you go, this is quick. If you haven’t, this is where year end gets expensive.
- Fixed assets: any significant equipment purchases (vans, tools, machinery) need to be recorded properly. These aren’t just expenses; they’re depreciated over time, which affects your tax position.
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Payroll year end
If you pay employees, including yourself as a director, there are separate payroll obligations that follow the 5 April tax year, regardless of when your company year end falls.
- 19 April: final Full Payment Submission (FPS) and Employer Payment Summary (EPS) due to HMRC. This closes out the tax year for payroll purposes.
- 31 May: P60s must be issued to every employee who was on your payroll on 5 April. Your payroll software should generate these automatically once you’ve completed your year-end processing.
- 6 July: if you provided any benefits in kind during the year (company van, private medical insurance, interest-free loans), these need to be reported on a P11D. This applies to directors too.
- 19/22 July: Class 1A National Insurance on any benefits in kind is due. The 22nd applies if you’re paying electronically; 19th by post.
Missing the P11D deadline costs £100 per 50 employees for each month late. It’s an easy one to forget because it falls in July, well after the rest of the year-end activity.
CIS: what field service businesses need to know
If your business operates in construction, fire and security, mechanical and electrical, or any sector where you pay subcontractors for labour on site, the Construction Industry Scheme (CIS) applies.
- As a contractor (you pay subcontractors): you must deduct 20% from labour payments to registered subcontractors, or 30% from unregistered ones. You submit a monthly CIS return to HMRC by the 19th of each month reporting what you’ve paid and deducted. Getting this wrong, or missing returns, triggers automatic penalties.
- As a subcontractor (a contractor deducts from your payments): those deductions, called CIS suffered, aren’t lost. As a limited company, you can offset them against PAYE and National Insurance you owe by reporting them monthly on your EPS. Anything left over at 5 April is claimed back through your corporation tax return.
The problem most businesses run into: they don’t track CIS suffered month by month, don’t submit EPS correctly, and then find at year end they’ve either overpaid tax or missed the window to reclaim. HMRC estimates around £200 million in CIS refunds go unclaimed each year.
If CIS applies to your business, make sure your accountant is reconciling it throughout the year, not just at year end.
What you can claim
Most field service businesses have more deductible costs than they realise. These reduce your taxable profit, so it’s worth making sure nothing is missed.
Commonly claimed and often overlooked in field service: vehicle costs (fuel, repairs, insurance, though not personal commuting), tools and equipment, work clothing and PPE, materials used on jobs, subcontractor costs, insurance, phone and data costs proportional to business use, training directly related to the work, accountancy fees, and software subscriptions including job management tools.
Business entertaining, such as taking clients out for dinner, is not deductible. HMRC’s rule is that expenses must be wholly and exclusively for business purposes. If you’re unsure whether something qualifies, ask your accountant before claiming it, not after.
One to watch: personal spending through the company. Putting non-business costs through the company and calling them expenses is one of the most common reasons HMRC opens an investigation. If a claim can’t be justified with a receipt and a clear business reason, it shouldn’t be in the accounts.
Common mistakes
- Overdrawn director’s loan account: if you’ve taken money from the company beyond your salary and dividends, that’s a director’s loan. If it’s still outstanding nine months after your year end, the company faces a Section 455 tax charge of 33.75% on the outstanding balance. The charge is reclaimed when the loan is repaid, but the cash flow impact can catch businesses off guard. Speak to your accountant before your year end if you think this applies.
- Late filing: HMRC and Companies House both issue automatic penalties for late accounts and returns. Filing late also increases your risk profile for future compliance checks.
- Mismatched records: if your declared income doesn’t match what HMRC can see from bank data or other sources, expect a question. HMRC’s systems cross-reference data from multiple sources. Clean, consistent records are your best protection.
- Leaving everything to the accountant: accounts prepared in a rush from incomplete records cost more and carry more risk. The less work your accountant has to do reconstructing your year, the better.
How Fieldmotion helps at year end
Most of the friction at year end comes down to records. If job sheets aren’t signed off, invoices aren’t matched to jobs, or materials costs haven’t been logged, someone has to piece it together. That someone is usually you, the week before the deadline.
Fieldmotion keeps job records, labour time, materials, and invoicing in one place throughout the year. When year end arrives, the information your accountant needs is already there: completed jobs, costs attached to each one, invoices raised and paid.
That matters for CIS too. If you need to reconcile what you’ve paid subcontractors and what deductions were made, clean job-level records make that process considerably faster.
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FAQs
When does a limited company’s year end fall?
It depends on when your company was incorporated and whether you’ve changed it. By default, Companies House sets your year end as the last day of the month in which you incorporated. You can find your current year end date by searching for your company on the Companies House register. Many businesses align their year end to 31 March to roughly mirror the personal tax year.
What’s the difference between my company year end and the tax year end?
The UK personal tax year runs from 6 April to 5 April. Your limited company has its own accounting year end, which can fall on any date. Payroll obligations (P60s, P11Ds) follow the 5 April tax year. Corporation tax and company accounts follow your company’s year end.
Do I need to worry about Making Tax Digital?
MTD for Income Tax (MTD ITSA) applies to sole traders and landlords, not limited companies. Limited companies are already required to file corporation tax returns digitally. The main change coming is that HMRC’s old CT600 online filing service closes in April 2026, so all company tax returns will need to go through commercial software from that point.
What records does HMRC expect me to keep?
You’re required to keep business records for at least 6 years from the end of the accounting period they relate to. This includes invoices, receipts, bank statements, payroll records, and any CIS deduction statements if the scheme applies to your business.
